A Group III nitride-based compound semiconductor light-emitting device has been widely used, and its characteristics are being extensively improved. A Group III nitride-based compound semiconductor light-emitting device is generally produced by epitaxially growing a Group III nitride-based compound semiconductor on a sapphire substrate or other hetero-substrate. It is an important task to improve light extraction efficiency in this semiconductor light-emitting device. To improve external light extraction efficiency, Patent Document 1 discloses that a dielectric made of SiO2 etc., having a lower refractive index than that of GaN is formed in a stripe pattern on a sapphire substrate, and GaN is grown from an exposed surface of the substrate to cover the top surface of the dielectric by vapor phase epitaxy.
Patent Document 2 discloses that a plurality of grooves is formed in a stripe pattern in parallel to a m-axis direction on an a-plane sapphire substrate, and GaN is grown from c-plane side surfaces of the grooves, in the c-axis direction perpendicular to the side surfaces, thereby GaN having a m-plane main surface is formed. Thus, in Patent Document 2, GaN having a main surface which is a non-polar plane is obtained.